Field of Invention
The present application is in the field of light emitting diode (LED) lamps and related methods.
Background of the Invention
An LED is a two-lead semiconductor light source. LEDs have become widespread for use in lighting applications because LEDs are favorably smaller in size, lower in power consumption, longer in life, and offer quicker response speeds than alternative incandescent or fluorescent light sources. Although better than alternative light sources, LED lamps can be inefficient, where in some cases, 80% to 85% of input power is converted to heat rather than light. This inefficiency can result in heat buildup and, if the heat is not dissipated effectively, light emitting intensity and service life of the LED light source are reduced significantly.
LED lamps or light bulbs are assemblies with an LED light source for use in lighting fixtures and other lighting applications. A traditional (prior art) LED bulb or lamp is an MR-16 high power LED lamp. FIG. 1A is a prospective view of a typical MR-16 high powered LED lamp bulb 10. FIG. 1B is a side view of the MR-16 high powered LED lamp bulb 10 of FIG. 1A. FIG. 1C is an exploded view of the MR-16 high powered LED bulb of FIGS. 1A and 1B. Referring to FIG. 1A through 1C, and FIG. 1C in particular, a traditional MR-16 LED bulb 10 comprises a housing 11, a base 12, a driver circuit and pins 13, LED light source(s) 14, wiring 15, printed circuit board (“PCB”) for the LED(s) 16, a lens and/or optic 17, and a retainer ring 18. Typically, the LED light source(s) 14 is(are) secured to the PCB 16 and both (a) mechanically connected to the base 12 and (b) electrically connected to the driver and pins 13 via the wires 15 and screws 19. In use, the light source(s) 14 emit(s) light whenever the driver and pins 13 are electrically connected to a power source (not shown). The lens and optics 17 may be used to focus light emitted from the light source(s) 14 and the snap retainer ring 18 can secure the lens/optics 17 in place. Such traditional LED bulbs are tedious to assemble because, among other reasons, (a) the wiring 15 must be soldered or otherwise connected to the driver and pins 13 and LED light source(s) 14; the PCB 16 must be screwed into the base and housing via a screw driver; and, usually a spanner wrench and other special purpose tools must be had for dismantling and reassembling an LED lamp.
Another embodiment of typical LED lamps are generally shown and described by U.S. Pat. App. Pub. 2008/0174247 (published Jul. 24, 2008) by Yu et al. Referring to FIG. 1 of Yu et al. (reproduced as FIG. 1D in this specification), a traditional MR-16 LED bulb 10 comprises a housing 11, a base 12, driver and pins 13, an LED light source 14, wiring 15, insulation 16, a lens/optic 17, and a cover 18. Yu et al., ¶[0007]. Typically, the LED light source 14 is secured to the insulation 16 and both (a) mechanically connected to the base 12 and (b) electrically connected to the driver and pins 13 via the wires 15. Id. In use, the light source 14 emits light whenever the driver and pins 13 are electrically connected to a power source (not shown). Id. The lens/optic 17 may be used to focus light emitted from the light source 14 and the cover 18 can secure the lens/optic 17 in place. Such traditional LED bulbs are tedious to assemble because, among other reasons, the wiring 15 must be soldered or otherwise connected to the driver and pins 13 and LED light source 14.
Traditional LED lamps, like the MR-16 lamp, have also not adequately addressed the heat-dissipation problems associated with LED light sources. For instance, heat cannot be effectively dissipated from the LED light source in a traditional bulb because the LED is positioned on insulation or a PCB. As discussed above, heat build-up can degrade the LED and, if the LED is damaged, it is more cost effective and time-efficient to replace the entire lamp than tediously replace the LED. Likewise, when failure of driver circuitry or driver components occurs, these are equally difficult and impractical to replace. Thus, an improved LED lamp is needed that effectively dissipates heat from the LED light source and/or that allows damaged LED light sources and/or damaged driver circuitry to be easily replaced. All of these problems render such MR-16 bulbs unserviceable.
One attempt to meet the aforementioned need is disclosed by Yu et al. Specifically, Yu et al. discloses, with reference to Yu et al.'s FIGS. 2 (reproduced as FIG. 2 in this document), an LED lamp 20 with an LED light source 27, a housing 21, heat-dissipation glue 23, a circuit board 24, and a femininely threaded adapter 26. Id., ¶[0020]. The LED light source 27 is a threaded cylinder wherein the threads 271 are a negative electrode for the LED and the base of the cylinder is a positive electrode for the LED. Id., ¶[0024]. The circuit board 24 features pins 25 and a positive contact point 241. As disclosed by Yu et al., the circuit board 24 and adapter 26 are glued, via the heat-dissipation glue 23, into the bottom of the housing 21 so that the circuit board 21 is underneath the adapter 26. Id. ¶[0021]. When so assembled, the LED light source 27 may be threaded, via its negative electrode 271, into the adaptor 26 until its positive electrode contacts the positive contact point 241 of the circuit board 24. Id., ¶[0021]. In this design: (a) heat may be transferred to the ambient environment via the mechanical contacts between the LED light source 27, adapter 26, circuit board 24, glue 23, and the housing 21; and (b) the LED light source 27 may be readily replaced via unscrewing the component 27 from the adapter 26.
Although an improvement to traditional LED lamps, the lamp disclosed by Yu et al. has various limitations. For instance, the threading of a small LED light source into an equally small adapter can be tedious and requires tools. In addition, a glue gun may be required in the assembly of the lamp. Furthermore, machining the threads for the LED light source and adapter of Yu et al.'s lamp requires exact tolerances or else the assembly cannot be constructed. Additionally, when a driver component or components fail, replacement is difficult since the driver 24 is glued into the housing 21 and may also require unsoldering and re-soldering of wires to effect such replacement. Finally, Yu et al.'s LED lamp accomplishes heat transfer to the ambient environment via the conduction of heat through the interface of several components of the lamp, which is less efficient than conductive heat transfer through the interface of two or less components of the lamp. Thus, a need still exists for LED lamps that effectively dissipate heat from an LED light source and that allow damaged LED light sources and drivers to be easily replaced.